Cameron Diaz has revealed she has toned down her ladette behaviour in Colin Firth's company.

The Bad Teacher star is filming the remake of Gambit with the Oscar-winning actor, who she describes as "delicious", and reckons she has become more of a lady.

"He is so refined and now I am 38, I don't behave like that any more. I have become more refined in the last six months - actually, since I knew I was doing a movie with Colin Firth," she said on The Graham Norton Show.

And Cameron confessed working with her ex Justin Timberlake in Bad Teacher was "heaven".

"We love each other as friends and we love to laugh together. Making a movie together was great. It was heaven," she revealed.

The actress added: "Nothing that we are doing in the film is sexy. We made a conscious effort to make the least sexy sex scene that has ever been caught on film and I really believe we succeeded.

"I don't think I could have achieved it with a guy I didn't know and didn't know where the boundaries were but it is so clearly defined between Justin and I because we're such good friends and we've been there and done that."

:: Bad Teacher is in cinemas now. The Graham Norton Show airs on Friday on BBC One at 10.35pm.